A stabilizer control apparatus for a vehicle is generally configured to reduce or minimize a roll motion of a vehicle body by applying an appropriate roll moment to the vehicle body by the use of actuation of stabilizer bars while the vehicle is turning. In order to implement such roll stabilizing function, for example, a known stabilizer assembly for a vehicle is configured so as to connect/disconnect between a pair of right and left stabilizer bars, which is arranged at right and left wheels, respectively, by means of a clutch mechanism. In particular, a semi-active anti-roll system described in JP2002-137619A (hereinafter referred to as Patent document 1) serving as a stabilizer assembly for a vehicle has a pair of wheels arranged away from each other in a transverse direction. Such stabilizer assembly includes first and second stabilizer members and a clutch assembly. Each of the first and second stabilizer members is connected to one of the wheels arranged away from each other in the transverse direction. The clutch assembly connected to the first and second stabilizer members is operable in first and second states. In the first state of the clutch assembly, the first and second stabilizer members rotate independently from each other so as not to transmit an operating force of one of the wheels to the other wheel. In the second state of the clutch assembly, the first and second stabilizer members are connected to each other so as to rotate integrally with each other in order to avoid rolling of a vehicle body.
In the stabilizer assembly described in Patent document 1, the clutch assembly is arranged between the first and second stabilizer members (including torsion bars and referred to as stabilizer bars), thereby connecting/disconnecting the first and second stabilizer members. Accordingly, when the vehicle body rolls, an extremely large torque is applied between the first stabilizer member and the clutch assembly and between the second stabilizer member and the clutch assembly. Consequently, it is necessary to firmly connect the clutch assembly to the first and second stabilizer members, thus requiring a large clutch assembly (actuator). As a result, it is required to expand the manufacturing process of the stabilizer assembly, thereby increasing the cost of the stabilizer assembly. Further, since the clutch assembly is arranged between the first and second stabilizer members, the clutch assembly may make contact with a road surface when the vehicle runs on a rough road. Furthermore, the clutch assembly integrally rotates with the first and second stabilizer members, therefore requiring a sufficient installation space for preventing the clutch assembly from making contact with the vehicle body.
On the other hand, for example, in the case of a stabilizer assembly for a vehicle, which includes a non-divided stabilizer bar, both ends of the stabilizer bar are supported by right and left wheels of the vehicle, respectively, and the stabilizer bar is supported by at least two supporting members arranged in an intermediate portion of the stabilizer bar. Further, a switching device is arranged between one of the supporting members and the vehicle body. The switching device arranged between one of the supporting members and the vehicle body is switched over from an extendable/retractable position to a neutral position corresponding to the time when the vehicle body is retained in a horizontal position, and vice versa. With such configuration of the stabilizer bar, the above-mentioned drawbacks may be prevented. However, when such switching device including a general mechanism is applied, the stabilizer assembly requires a fluid pressure source and a screw mechanism, thereby increasing the size. Consequently, a drawback such as the occurrence of a complicated and expensive stabilizer assembly may occur.
A need thus exists for a stabilizer control apparatus, which is not susceptible to the drawbacks mentioned above.